PROPELLANT COMPOSITIONS COMPRISING NITRAMINE OXIDANTS

Abstract

The present invention relates to a high energy-containing propellant composition and a use thereof. The propellant composition of the present invention is a propellant composition for guns, including: (a) 55 to 85 wt % of a nitrocellulose binder; (b) 10 to 35 wt % of a nitramine oxidant; (c) 1 to 4 wt % of a plasticizer having both a nitrate group and a nitramine group; and (d) 0.5 to 3 wt % of a stabilizer. The propellant composition of the present invention significantly improves a physical compatibility between the nitrocellulose binder and the oxidant using a plasticizer containing both a nitrate group and a nitramine group, leading to stable interior ballistics characteristics from low temperature to high temperature as well as improvement on the characteristics of an extrudate. Accordingly, the propellant composition of the present invention may be effectively applied to an ammunition for guns due to an excellent physical property and interior ballistic stability thereof.

Claims

1. A propellant composition for guns, comprising: (a) 55 to 85 wt % of a nitrocellulose binder; (b) 10 to 35 wt % of a nitramine oxidant; (c) 1 to 4 wt % of a plasticizer having both a nitrate group and a nitramine group; and (d) 0.5 to 3 wt % of a stabilizer.

2. The propellant composition of claim 1, wherein a nitrogen content in the nitrocellulose binder is 12 to 14 wt %.

3. (canceled)

4. (canceled)

5. The propellant composition of claim 1, wherein the plasticizer having both the nitrate group and the nitramine group is alkyl-nitrate ethyl nitramine (alkyl-NENA).

6. (canceled)

7. The propellant composition of claim 1, wherein the propellant composition has stable interior ballistics characteristics at a temperature of −40° C. to 52° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1 is a result showing a 7-hole cylindrical extrudate prepared using propellant compositions 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, the present invention will now be described in further detail by examples. It would be obvious to those skilled in the art that these examples are intended to be more concretely illustrative and the scope of the present invention as set forth in the appended claims is not limited to or by Examples.

Example

1. Preparation of Propellant Compositions

[0038] As solvents, Acetone (Daejung Chemical & Metals Co., Ltd., Korea), ethyl acetate (Daejung Chemical & Metals Co., Ltd., Korea) and diethyl ether (Daejung Chemical & Metals Co., Ltd., Korea) were put into a Sigma Blade Mixer (Fine Machinery Ind. Co., Ltd., Korea), and then nitrocellulose (Hanwha Corporation, Korea) was added thereto and dissolved. After complete dissolution, a mixture containing a nitramine solid oxidant, a plasticizer and a stabilizer was added into the mixer and sufficiently mixed. The solvent was evaporated until the mixture had a suitable viscosity, and then the mixture was tightly sealed to prevent additional evaporation of the solvent. The kneaded/obtained mixture was put into a RAM PRESS (Boo Young Precision Tool Co., Ltd., Korea) equipped with a propellant mold, and was extruded by adding pressure thereto. After the extrudate was cut into a predetermined size to make a grain form, it was dried at normal temperature overnight, and then further dried at 50 to 60° C. for about 3 days. So as to prevent generation of static electricity in the propellant grains, graphite (Asbury Carbons, USA) was dry coated on the surface of the grain.

2. Constitution of Propellant Composition and Study on Characteristics Thereof

[0039] As described above, the constitutions of Composition 1, Composition 2, and a Control (Reference propellant) are as follows:

[0040] (a) Composition 1—Nitrocellulose 85%, RDX (Hanwha Corporation, Korea) 10%, BuNENA (Hanchem Co., Ltd., Korea) 3% and Akadite II (Synthesia, a.s, Czech Republic) 2%;

[0041] (b) Composition 2—Nitrocellulose 75%, RDX 20%, BuNENA 3% and Akadite II 2%; and

[0042] (c) Control (Reference propellant)—Single base propellant composed of nitrocellulose.

[0043] For the prepared propellants of Composition 1 and Composition 2, an abnormal phenomenon such as crumbling of the kneaded product did not occur during the mixture of raw materials, and the surface of the extrudate was smoothly extruded when the kneaded product was extruded as a 7-hole cylindrical form. Further, when a grain shape was produced by cutting the extrudate, an abnormal phenomenon such as bubble generation and clogging of perforation holes was not observed (See FIG. 1).

[0044] Subsequently, the present inventors investigated a change in interior ballistics characteristics according to the temperature by using the propellant grains of Composition 1 and Composition 2 to charge a 40-mm ammunition with the propellant.

TABLE-US-00001 TABLE 1 Comparison of Characteristics between Propellant Compositions of Present Invention and Conventional Single Base Propellant according to Change in Temperature. Classification −40° C. 21° C. 52° C. Composition Propellant charge 1 weight 390 g Muzzle velocity (m/s) 1250 1300 1330 Maximum pressure 300 334 351 in chamber (Mpa) Composition Propellant charge 2 weight 390 g Muzzle velocity (m/s) 1320 1360 1380 Maximum pressure 351 386 413 in chamber (Mpa) Reference Propellant charge Propellant weight 390 g (Single Base Muzzle velocity (m/s) 1250 1290 1320 Composition) Maximum pressure 305 344 364 in chamber (Mpa)

[0045] As can be confirmed in Table 1, the Propellant Compositions 1 and 2 exhibited stable interior ballistics characteristics at all the tested temperatures (−40° C., 21° C. and 52° C.) without any abnormal phenomenon such as an abnormal pressure increase in chamber. Further, when an ammunition was equally charged with the propellant charge weight of 390 g, the Propellant Composition 1 exhibited a suitable interior ballistics results as a propellant for use in guns, which had low maximum pressure and high muzzle velocity at all the tested temperatures compared with the Reference Propellant (Single Base Composition). In addition, it could be demonstrated that the Propellant Composition 2 is a high-energy propellant composition in which the muzzle velocity is remarkably enhanced at a normal temperature condition (21° C.) compared to the Reference Propellant. It is appreciated that the Propellant Compositions 1 and 2 may be efficiently used in a high-performance ammunition when considering the interior ballistics characteristics thereof.

[0046] Although the specific part of the present disclosure has been described in detail, it is obvious to those skilled in the art that such a specific description is just a preferred embodiment and the scope of the present invention is not limited thereby. Therefore, the substantial scope of the present disclosure will be defined by the appended claims and equivalents thereof.